Social insects provide an ideal model system to study how reproduction, resource flow, and societal status (caste) influences age-specific mortality schedules. Its colony life history and caste structure are simple, with a well-defined differentiation between the reproductive queen and the reproductively quiescent workers, driven by the availability of food resources. Workers display exceptional plasticity as adults, assuming different behavioral roles with aging rates strongly dependent on the behavioral and physiological changes and reproductive opportunities. This proposal has four specific aims: 1. determine causal relationships between larval nutrition, ovary size, reproductive hormones, and life span; 2. determine effect of adult protein feeding on life history and life span; 3. determine direct effects of vitellogenin on extreme life span; 4. determine life span consequences of worker reproduction. The first objective will be met with four experiments differentiating between the genotypic and ovary effects, ovary and vitellogenin effects, and ovary and juvenile hormone effects on life history and life span. The second objective will be addressed by differential feeding of newly-emerged workers and vitellogenin knock down in a third experimental group. The third objective will target the long- lived diutinus worker caste and in three experiments determine its dependency on reduced brood pheromone levels, juvenile hormone, and vitellogenin, and how the diutinus state affects subsequent lifespan for foragers and hive bees. These experiments will be conducted by a combination of social manipulations, brood pheromone and methoprene (a juvenile hormone analogue) application, and vitellogenin knock down, using a race of honey bee (Apis mellifera mellifera) that has a pronounced diutinus subcaste. Objective four will be achieved in four experiments comparing the life- course dynamics of behavior, mortality, and gene expression patterns between reproductive and non-reproductive workers. Intensive social manipulations will enable comparisons with brood rearing, with perceived brood presence by pheromone application, or in total absence of brood. All experimental procedures are standard or have already been established in our groups. RELEVANCE (See instructions): Why does the probability of death increase with age? Why do some people live much longer than others? These are critically important questions for society today and require comprehensive study in a variety of biological models. Perhaps we can find some answers to these questions through comparative studies of other species, especially those that, like us, live their lives in social groups.